I am in the process of trying to add the functionality of the SDrive as a daughter card onto the main board. It will be offered as an option. The basic board is nearly finished. Here's a couple of renderings of what it would look like.

And then finally the front panel that will bolt onto the two brackets to provide control and display.

I'll be running some confirmation tests on the 'PSU Control Interface' early next week and post the results here. Basically this interface allows the XEL to switch ON and OFF the PSU's high current and 12V outputs via the same mechanism that switches on it's own main power bus. And the XEL will derive it's power supply from the PSU's standby circuit, which is limited to 2 amps max (more than sufficient for the XEL's needs). The PSU's normal 5V and12V supplies will of course be used by Dropcheck's XF551 board and floppy drive.

For hooking up the XF551 board internally, the XEL has a SIO AUX Port header that can likely supply it's needs...

Sorry but we ran into some serious problems in our beta tests with the first two builds that currently defy logic. Since these people are very vested into this project I have to tackle this first. But I promise I will get back to the PSU tests soon.

Reimaged XF551 mainboard to fit within a 3 1/2" drive bay connected to the 1088XEL's Aux SIO connector. ATX12V/EPS12V compatible adapter board to enable a normal PC case power supply for drive mech power. SDriveXEL pcb will be stacked atop the XF551XEL board and contain circutry for SDrive. Front facing pcb with track display, 4in1OS and drive # selector switch, reset and power led and leds and control buttons for the SDriveXEL.

None of the XF551XEL boards will include the Intel 8040/8050, WD1772 or the eprom OS chips, and some of the part images depicted will not be exactly the same, but otherwise this is a very close representation of what you will recieve not including the data cabling for the drive and the power cables for the board.

But the SDrive NUXX is already published with schematics and gerber files. I've simply modified some of the parts and layout to work with my design. You are welcomed to come up with your own implementation for the 1088XEL project though.

The ATX12V adapter is a companion board to allow easier usage with a normal ATX12V power supply. As it is, the board is just the power receptacle and pcb tracing to a three wire connector to mate with the AUX power connector on the 1088XEL. Hardly a secret piece of engineering. Again you are welcomed to design your own or buy other ready made products to accomplish that.

The XF551 project is also not a secret piece of engineering, but after putting in a ton of time and effort to get it up and running both in it's original form and in this project, I am understandably not willing to release my work on it to open source yet. I am actively still producing and supporting the product. Again you are welcomed to design your own. The Atari source information is available.

After more deliberation I've decided to offer the SDriveXEL as a standalone option as well. It will be completely populated and completely separate from the XF551XEL board.

Cost will be $45.00 plus shipping.

Here's a couple of renderings of what to expect. Again the parts won't be exactly the same, but it does give you an idea of the way it will look.

One other thing I've been toying with:

On the sandwiching of the boards for the complete XF551 with the SDrive option, I am becoming increasingly concerned at the height restrictions for the 3 1/2" drive bay. I tried a couple of designs to see if I could get the height down. The most satisfactory design ended up being the more costly design. Go figure.

On the original design you needed a total of three boards to have the complete features of track display, front controls, SDrive and XF551 circuitry. On the this newer design, I've put all but the controls, leds and display on a single 4 layer pcb. That means just the mainboard and the front panel, only 2 boards needed. But that meant a more expensive board because of the 4 layers and the size of the mainboard. It's added almost $16 more to the cost for both option 2 and 3.

Now there's no economic way to do both. So one or the other is going to be the baseboard of options 2 and 3.

Depending on the option you chose some of the parts will not present, but here is a rendering of the 4 layer pcb.

Due to some sleuthing by Mytekcontrols, the new combined mainboard option should be cheaper than originally thought. It might be a more realistic $3-5 more. So at this point I feel reasonably confident that I will be using the combined 4 layer board for options 2 and 3.